The ongoing summit eruption at Kīlauea Volcano, Hawai‘i, began in March 2008 with the formation of the Overlook crater, within Halema‘uma‘u Crater. As of late 2016, the Overlook crater contained a large, persistently active lava lake (250 × 190 meters). The accessibility of the lake allows frequent direct observations, and a robust geophysical...

Paleomagnetic data for samples collected from outcrops of basaltic spatter at the Ubehebe Crater cluster, Death Valley National Park, California, record a single direction of remanent magnetization indicating that these materials were emplaced during a short duration, monogenetic eruption sequence ~ 2100 years ago. This...

The geologic map of the northern half of the Lake Walcott 30ʹ×60ʹ quadrangle shows the volcanic geology of the southern part of the Craters of the Moon lava field, the complex geologic features of the Holocene Kings Bowl and Wapi lava fields, and the southern part of the Great Rift volcanic rift zone. The long extent and distribution of skylights...

When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U....

In early May 2018, Kīlauea volcano became increasingly active, posing an increase in threat to respiratory health. The emission of gases such as sulfur dioxide from Kīlauea produces large amounts of respirable acid particles as the gases react with water vapor and sunlight, resulting in a visible haze called “vog”. Additionally, the lava lake at...

A fundamental goal of igneous petrology is to quantify the duration of time required to produce evolved magmas following influx of basalt into the crust. However, in many cases, complex field relations and/or the presence of a long-lived magmatic system make it difficult to assess how basaltic inputs relate to more evolved magmas, therefore,...

Lahar, an Indonesian word for volcanic mudflow, is a mixture of water, mud, and volcanic rock flowing swiftly along a channel draining a volcano. Lahars can form during or after eruptions, or even during periods of inactivity. They are among the greatest threats volcanoes pose to people and property. Lahars can occur with little to no warning, and...

We present a detailed geologic investigation of Pleistocene to Holocene mafic volcanism within the northernmost part of the Harrat Rahat volcanic field, proximal to the city of Al-Madinah, Saudi Arabia. Our study area covers ∼570 km2, and encompasses lava flows, scoria cones, and shield volcanoes of 32 mapped eruptive units consisting of...

Geologists recognize lavas and ash deposits from about 60 past eruptions in the area around Mammoth Mountain and Devils Postpile, California. This raises the unanswerable question, “When will it erupt again?” An alternative, answerable, and informative question is, “How often has it erupted?”In the Mammoth Lakes Sierra, geologists have mapped in...

Lahars large enough to reach populated areas are a hazard at Mount Adams, a massive volcano in the southern Cascade Range of Washington State (fig. 1). It is considered to be still active and has the potential to erupt again. By definition, lahars are gravity-driven flows of water-saturated mixtures of mud and rock (plus or minus ice, wood, and...

We conducted travel time tomography using P- and S-wave arrival times of volcanic-tectonic (VT) events that occurred between November and December 2013 to determine the three-dimensional (3D) seismic velocity structure (Vp, Vs, and Vp/Vs) beneath Sinabung volcano, Indonesia in order to delineate geological subsurface structure and to enhance our...

Annually averaged solar radiation in the McMurdo Dry Valleys, Antarctica has varied by over 20 W m−2 during the past three decades; however, the drivers of this variability are unknown. Because small differences in radiation are important to water availability and ecosystem functioning in polar deserts, determining the causes are important to...

I am a Research Geophysicist within the Geomagnetism Program of the U.S. Geological Survey (USGS). My research has, over the years, covered a variety of subjects related to the Earth's magnetic field. These days, I concentrate on using geomagnetic monitoring data and magnetotelluric survey data to evaluate geoelectric hazards that are a...

My work focuses on the dynamics of explosive eruptions—especially volcanic plumes and pyroclastic density currents. I take a field-based approach to reconstructing the processes recorded in volcanic deposits. But I also try to bring together diverse techniques (textural analysis, geophysics, remote sensing, modeling) to...

I am a Geologist with the U.S. Geological Survey at the Cascades Volcano Observatory in Vancouver, Washington. I specialize in volcano hazards assessment and risk research and applications for domestic as well as foreign volcanoes as a member of the Volcano Disaster Assistance Program, co-funded by the U.S. Geological Survey and the U.S....

Blaine McCleskey started his career with the U.S. Geological Survey in 1997 as a chemist in the National Research Program. In 2010, he obtained a Ph.D. from the University of Colorado where he developed a method to calculate the electrical conductivity of natural waters from its chemical composition. He is currently involved in several...